I will show you first of all by a concrete case the nature of the trauma and its psychological predisposition. A young lady suffered from severe hysteria after a sudden fright. She had been attending a social gathering that evening and was on her way home at midnight, accompanied by several acquaintances, when a carriage came behind her at full speed. Everyone else drew aside, but she, paralyzed by fright, remained in the middle of the street and ran just in front of the horses. The coachman cracked his whip, cursed and swore without any result. She ran down the whole length of the street, which led to a bridge. There her strength failed her, and to escape the horses’ feet she thought, in her extreme despair, of jumping into the water, but was prevented in time by passers-by. This very same lady happened to be present a little later on that bloody day, the 22d of January, in St. Petersburg, when a street was cleared by soldiers’ volleys. Right and left of her she saw people dying or falling down badly wounded. Remaining perfectly calm and clear-minded, she caught sight of a gate that gave her escape into another street. These terrible moments did not agitate her, either at the time, or later on. Whence it must follow that the intensity of the trauma is of small pathogenic importance: the special conditions form the essential factors. Here, then, we have the key by which we are able to unlock at least one of the anterooms to the understanding of predisposition. We must next ask what were the special circumstances in this carriage-scene. The terror and apprehension began as soon as the lady heard the horses’ foot-steps. It seemed to her for a moment as if these betokened some terrible fate, portending her death or something dreadful. Then she lost consciousness. The real causation is somehow connected with the horses. The predisposition of the patient, who acts thus wildly at such a commonplace occurence, could perhaps be found in the fact that horses had a special significance for her. It might suffice, for instance, if she had been once concerned in some dangerous accident with horses. This assumption does hold good here. When she was seven years old, she was once out on a carriage-drive with the coachman; the horses shied and approached the steep river-bank at full speed. The coachman jumped off his seat, and shouted to her to do the same, which she was barely able to do, as she was frightened to death. Still, she sprang down at the right moment, whilst the horses and carriage were dashed down below.